As explained in How does Cassandra store data? – A simple explanation Cassandra uses partitioning key (the first part of primary key) to store a record into a partition on a node. Prior to version 1.2, one server = one node. That is each machine was assigned to a range of values, so that the entire cluster covered … Continue reading Cassandra node vs partition: A simple explanation

Pattern #4: Get rid of all OR operators from sql where clauses. For example, consider an SQL requirement to authenticate user by comparing the string entered by the user with either username or email or phone: select u1.* from user u1 where (u1.username = ?1 or u1.email = ?1 or u1.phone = ?1) and u1.password = … Continue reading Migrating SQL applications to Cassandra – Pattern #4